This invention relates to computer systems and, more particularly, to a network wherein multiple users may share, perceive, and manipulate a virtual environment generated by a computer system.
Researchers have been working with virtual reality systems for some time. In a typical virtual reality system, people are immersed in three-dimensional, computer-generated worlds wherein they control the computer-generated world by using parts of their body, such as their hands, in a natural manner. Examples of virtual reality systems may be found in telerobotics, virtual control panels, architectural simulation, and scientific visualization. See, for example, Sutherland, W. R., "The Ultimate Display", Proceedings of the IPIP Congress 2, 506-508 (1965); Fisher, S. S., McGreevy, M., Humphries, J., and Robbinett, W., "Virtual Environment Display System," Proc. 86 Workshop 3D Graphics, 77-87 (1986); F. P. Brooks, "Walkthrough--A Dynamic Graphics System for Simulating Virtual Buildings", Proc. 1986 Workshop on Interactive 3D Graphics, 9-12 (1986); and Chung, J. C., "Exploring Virtual Worlds with Head-Mounted Displays", Proc. SPIE Vol. 1083, Los Angeles, Calif., (1989). All of the foregoing publications are incorporated herein by reference.
In known systems, not necessarily in the prior art, a user wears a special helmet that contains two small television screens, one for each eye, so that the image appears to be three dimensional. This effectively immerses the user in a simulated scene. A sensor mounted on the helmet keeps track of the position and orientation of the users head. As the user's head turns, the computerized scene shifts accordingly. To interact with objects in the simulated world, the user wears an instrumented glove having sensors that detect how the hand is bending. A separate sensor, similar to the one on the helmet, determines the hand's position in space. A computer-drawn image of a hand appears in the computerized scene, allowing the user to guide the hand to objects in the simulation. The virtual hand emulates the movements of the real hand, so the virtual hand may be used to grasp and pick up virtual objects and manipulate them according to gestures of the real hand. An example of a system wherein the gestures of a part of the body of the physical user is used to create a cursor which emulates the part of the body for manipulating virtual objects is disclosed in copending U.S. patent application Ser. No. 317,107, filed Feb. 28, 1989, U.S. Pat .No. 4,988,981, issued Jan. 29, 1991, entitled, "Computer Data Entry Manipulation Apparatus and Method," incorporated herein by reference.
To date, known virtual reality systems accommodate only a single user within the perceived virtual space. As a result, they cannot accommodate volitional virtual interaction between multiple users.